If you have ever driven your Nissan 350z on the highway on a hot sunny day with your pedal to the metal and your aircon on full blast, then you might have come across the temperature warning on your dashboard. This is a sign that your Nissan 350z is overheating.
The most common reason for your Nissan 350z to overheat is a coolant leakage or loss. Other causes such as the thermostat being damaged, or your water pump malfunctioning may also cause your car to overheat. In a few other cases, damage to the radiator fins or your cylinder head gasket may also cause inefficient cooling leading to an increased temperature in your engine compartment.
Before jumping into a detailed analysis of these problems and their solutions, let’s first look into why overheating can be a major problem.
Why is engine overheating such a big deal?
While running an engine in cold conditions will at the most consume some more fuel, running it in very hot conditions might cause the engine to stop working entirely. As you may know, when the engine is working, the pistons move up and down in their respective cylinders. Now, these pistons are made of metal and are subject to great amounts of heat.
What the big book of science tells us is that any metal when in contact with heat tends to expand. Thus, over time, the pistons get bigger and bigger in comparison to the cylinders they are moving inside. At some point, the piston expands so much that it cannot move inside the cylinder any more. This is known as Engine Seizure.
As the name suggests, this stops the pistons in your engine. At this point, your car moving no more is the least of your concerns. Not only is it a huge headache to get this fixed but also it would probably cost you a kidney on the black market. So, as they say, prevention is better than cure.
Why is my Nissan 350z overheating?
There are generally seven main reasons why your Nissan 350z may be overheating. These include:
- Lack of engine coolant
- Water pump issues
- A malfunctioning thermostat
- Cooling fan failure
- Damaged gaskets
- Damaged radiator
- Lack of engine oil
1. Lack of coolant
The function of the coolant is to absorb the heat from the engine. Thus, if there is a low amount of coolant, then the amount of heat absorbed reduces significantly. Moreover, the flow of the coolant is also poor through the engine and thus less heat can be absorbed in the same period.
The coolant in your engine needs to be topped off occasionally every couple of years or so since there is an inherent tendency to evaporate in hot operating conditions. However, excessive coolant loss is mostly caused due to a leakage in the system.
Since all the coolant is carried by hoses, there is always a chance of damage occurring. This damage can be exasperated due to the hot and highly pressurized liquid flowing inside it. These small cuts can easily occur while you were trying to fix another part in the same space. Other possible sources of leakages are near the sealing points of the water pump or the thermostat.
As the primary problem is a leakage, all you must do is find out the location of the leak and replace the concerned hose or seal. Do not attempt patchwork as the high-pressure coolant can easily make its way out of such temporary fixes.
2. Water pump problems
While the name of this component is the “water” pump, this part is responsible for circulating the coolant throughout the engine and the entire cooling circuit. Thus, if there is any problem with the water pump, then the coolant doesn’t flow as efficiently. This might be a reason why your 350z is overheating.
This is generally caused due to something getting stuck in the cooling jackets of the engine or water pump that is obstructing the flow. Usually, this is some form of sealant or a part of a gasket. Unfortunately, to fix this, you will have to disassemble the engine almost completely till you spot the blockage and then remove it.
3. Thermostat malfunctioning
The thermostat has a very important function in the cooling system of the car. You might know that the engine is to be kept in a certain temperature range. Thus, to ensure that the engine is not cooled down too much, sometimes instead of passing the coolant through the radiator, the thermostat just ensures that the cooling circuit is limited to the engine only. When the temperature of the coolant increases, the thermostat (essentially a valve) opens and allows the coolant to flow through the radiator and cool itself down.
The working of a thermostat relies on the spring-loaded mechanism. Thus, if the thermostat is not working properly, the spring might be stuck in one position not allowing the valve to open. Consequently, the coolant is stuck circulating through the engine which leads to a possible reason that your 350z is overheating.
Fortunately, the thermostat is also something that is kept on the outer layers of the engine and thus not too hard to replace. Unfortunately, it does involve draining all the coolant before you can work on it. After replacing the thermostat, remember to fill the coolant back up and avoid any air gaps in the coolant pipes. The air gaps may also lead to inefficiencies in the cooling process leading to overheating problems.
At this point, we feel it is important to mention that working on the cooling systems is a very dangerous task. The coolant generally operates at around 85-100 degrees C and this heat creates a lot of pressure too. There is even a convenient warning right on the radiator cap but often it seems to get ignored. The pressurized coolant can splash out easily and burn you. Be careful not to work on the engine when it is hot. Allow everything to cool down properly before you do.
4. Failing Cooling Fan
Just like the thermostat, the cooling fan is supposed to switch on only when necessary to provide additional cooling to the radiator. Thus, if the temperature reaches a certain point and your cooling fan still does not activate, it is probably malfunctioning. Since the radiator needs the cooling fan at this temperature point, not having it might be a reason why your 350z is overheating.
This can be caused either due to a failure in temperature sensing or the relay not functioning. In either case, the solution is to simply replace either of these components. It can be done easily at the dealership nearest to you.
5. Damaged gaskets
As the engine grows older, there is a tendency for the sealing action of the gasket to be compromised. Two main gaskets of concern are the cylinder head gasket and the thermostat gasket. The latter is fairly simple to replace as every new thermostat comes with its own gasket.
The former can turn into a huge problem. While very low amounts of coolant leaking into the cylinder is not a huge concern as the heat will vaporize all of it almost instantly. However, this may turn into a bigger problem in the future. Significant volumes of liquids cannot be compressed by the piston and thus it leads to catastrophic failure of the engine.
An easy way to identify when coolant is burning is to check the color of your exhaust emissions. White smoke generally indicates that the coolant has leaked into the cylinder and is being evaporated. Thus, if you feel like your engine is overheating, and catch a glimpse of white smoke from the tailpipe, get your engine checked immediately. Just a warning, this might end up costing a lot as it involves disassembling the engine down to a considerable level.
6. Damaged Radiator
The job of the radiator is to dissipate the heat of the coolant via very thin fins attached to it. Since these fins are very thin, they can get damaged very easily. On the off chance they do, it affects the cooling performance of the radiator. Thus it can lead to your engine overheating as well.
But rest assured, the only time a radiator like this is damaged is if someone tries to pressure clean it with water. Thus, remember to take your car to a respectable auto mechanic for servicing (preferably a Nissan certified dealer), or else it may come back to bite you in the back.
7. Engine Oil problems
There was one problem not discussed earlier in the introduction and that is a lack of engine oil. While the main function of engine oil is to lubricate all the moving parts, an auxiliary function is to cool the engine down as well. Now, this engine oil gets frequently used up as a portion of it may burn during combustion. Thus, it is important to check the engine oil level rather regularly and top up if necessary.
When there is a lack of engine oil, it increases the friction between components which in turn leads to heat generation. Moreover, the cooling action is also reduced. Thus, there is a chance of your Nissan 350z overheating even if the engine oil is low.
On the bright side, this is the easiest fix on the list. Just top off the engine oil after checking the level.
The problem of engine overheating is a tricky one. It can be a simple problem like a lack of coolant or engine oil. Or it could also be something more complicated like a damaged head gasket leaking coolant into your cylinder. Thus, it is important to be on the lookout for the temperature warning in the car. Do not ignore it or wait for your engine to start smoking up. At the same time, keep an eye on the “check engine” warning. This may indicate any of the problems mentioned above as well.
When you do notice the temperature warning, check your oil and coolant levels first. If they are within limits, then it is possibly a problem with one of the other components mentioned in this article. For these fixes, we highly recommend getting it checked at a certified dealer. These parts can be hard to access and dangerous to handle. But if you have the right tools for them and are rather confident in your DIY skills, then Godspeed comrade!
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